The present teachings are predicated upon providing an improved brake system for use with vehicles. For example, the brake system may be used with almost any vehicle (e.g. car, truck, bus, train, airplane, or the like). Alternatively, the brake system may be integrated into assemblies used for manufacturing or other equipment that require a brake such as a lathe, winder for paper products or cloth, amusement park rides, wind turbines, the like, or a combination thereof. However, the present teachings are most suitable for use with a passenger vehicle (i.e. a car, truck, sports utility vehicle, or the like). Typical, brake systems used have a floating caliper, a fixed caliper, or are a drum brake system as is discussed below.
A typical drum brake system includes an enclosed drum with friction plates located inside. During running there is a gap between an internal circumference of the drum and an outer surface of the brake pads or shoes. During a brake apply the brake pads or shoes are moved radially outward into contact with the drum so that a braking force is created. Some examples of drum brakes may be found in U.S. Pat. Nos. 2,129,199; 5,025,898; and 7,325,659.
Generally, a floating caliper braking system includes a rotor, a caliper body, a support bracket, and an inboard brake pad and an outboard brake pad located on opposing sides of the rotor. The caliper body further includes a bridge, one or more fingers, and a piston bore. The piston bore houses a piston. The piston bore has a bore axis that the piston moves along during a brake apply and a brake release. The piston bore may include a fluid inlet, a closed wall, a front opening, and a cylindrical side wall that has a seal groove located near the front opening. Typically, the fluid inlet is located in the closed wall of the piston bore so that when pressure is applied the fluid will flow into the piston bore and push the piston towards the front opening and into contact with a brake pad and then the brake pad into contact with a rotor. The caliper housing, upon the brake pad contacting the rotor, moves so that the one or more fingers contact the opposing brake pad and then move the opposing brake pad into contact with the opposing side of the rotor so that a braking force is created. Some examples of floating style disc brakes may be found in U.S. patent application Ser. Nos. 3,260,332; 3,997,034; 4,342,380; 4,681,194; 4,716,994; and 7,357,228 all of which are incorporated by reference herein for ail purposes.
Generally, a fixed caliper braking system includes a rotor, a caliper body, a support bracket, and an inboard brake pad and an outboard brake pad located on opposing sides of the rotor. The caliper body includes a bridge, an inboard piston bore having an inboard piston, and an outboard piston bore having an outboard piston. The outboard piston and the inboard piston are located on opposite sides of the rotor so that during a brake apply both pistons move each respective brake pad into contact with the respective sides of the rotor. During a brake apply, the caliper remains generally static as the inboard piston and the outboard piston travel toward each other moving the respective brake pad into contact with opposing sides of the rotor so that a braking force is created. Some examples of fixed disc brake systems may be found in U.S. Pat. Nos. 5,099,961 and 6,367,595 all of which are incorporated by reference herein for all purposes.
Examples of additional brake systems are found in U.S. Pat. Nos. 3,802,539 and 6,318,513; U.S. Patent Application Publication Nos. 2006/0260886; 2008/0261773; and 2010/0258387; and International Patent Application Publication No. WO98/29671; WO2005/038282; WO2005/038285; WO2005/038287; and WO2006/047886. However, some of these systems include multiple parts to function, are complex and difficult to assemble and repair; or both, thus, may create challenges in assembly and serviceability.
It would be attractive to have a brake system that has lower fewer parts so that complexity of the brake system is reduced and assembly and serviceability are simplified. It would be attractive to have a device with a reduced number of parts that provides improved braking performance. What is needed is a device that reduces the mass and/or number of parts while maintaining a low taper wear for the brake pads, low disc thickness variation (DTV) of the rotor and low brake torque variation (BTV) of the brake pads so that the full contact brake provides improved NVH performance and the operator and/or passengers do not experience any adverse effects on the system. The teachings herein provide a brake system that includes a pair of opposing brake pads and a rotor that have substantially equal surface areas so that during a brake apply the entire inboard and outboard circular rings, or plates, of the rotor and brake pads are contacted simultaneously. What is needed is a brake system that is configured so that during a brake apply the pistons, brake pads, or preferably both are free of rotation with the rotor without the use of mechanical locking devices.